Barcelona's Digital Archive Push Tackles Duplicate Image Crisis Across City Databases

Barcelona's city administration confirmed this week that a coordinated duplicate-image replacement drive is now underway across at least six municipal digital archives, targeting tens of thousands of redundant photo files that have accumulated in public databases since the early 2010s. The effort, coordinated through the Ajuntament de Barcelona's Institut de Cultura (ICUB), involves both automated detection software and manual review teams working from offices at Palau de la Virreina on La Rambla.

The timing is not incidental. Barcelona is in the middle of expanding its open-data infrastructure ahead of a planned upgrade to the Cartipàs Municipal — the city's official register of public information — scheduled for the fourth quarter of 2026. Duplicate and mismatched image records have been identified as one of the main obstacles slowing that upgrade, because they create conflicting metadata entries that downstream systems, including the city's tourism and urban planning portals, cannot reconcile automatically.

What the Audit Found

The review, which began formally on 30 June, has so far flagged more than 22,000 image files across three primary repositories: the Arxiu Fotogràfic de Barcelona based in the Born neighbourhood, the digital asset library maintained by Barcelona Turisme, and the internal image bank used by the Ajuntament's communications department at Plaça de Sant Jaume. In each case, auditors found the same photographs stored under multiple file names, different compression settings, and occasionally contradictory licensing tags — a legacy of years of independent uploading by separate departments with no shared naming convention.

The Arxiu Fotogràfic alone, which holds more than 4 million digitised images spanning the 19th and 20th centuries, had approximately 8,400 flagged duplicates as of Thursday. Archivists there are using a perceptual hashing tool — software that generates a fingerprint for each image based on visual content rather than file name — to catch near-identical copies that differ only in resolution or cropping. The approach is more reliable than simple filename matching, which missed a significant share of redundant files in an earlier, smaller trial conducted in late 2025.

The practical stakes are higher than they might appear. Barcelona's short-term rental crackdown, ongoing under Mayor Jaume Collboni's administration, has generated an enormous volume of documentation — inspection photos, property records, enforcement images — that feeds into the city's housing enforcement platform. Duplicate image entries in that system have, on at least a handful of occasions this year, caused enforcement case files to display incorrect property photographs, a problem that case officers flagged to IT administrators in May. Correcting those errors manually has taken staff time that the new automated process is intended to eliminate.

Next Steps and Practical Impact

ICUB has set a working deadline of 31 August to complete the first phase of replacements across the three primary repositories. A second phase, covering smaller departmental image banks including those maintained by the Museu Picasso on Carrer de Montcada and the Palau de Congressos de Barcelona near Diagonal, is pencilled in for the autumn. The Museu Picasso holds one of the most frequently accessed public image catalogues in the city, with its online collection drawing requests from researchers across Europe.

For residents and researchers who use the city's open-data portal, the most visible change will come when the updated Cartipàs Municipal launches later this year — search results for neighbourhood photographs, planning documents, and cultural event archives should return cleaner, non-duplicated results. Professionals working with the city's APIs, including the growing cluster of urban-tech startups operating out of coworking spaces in Poblenou's 22@ district, have already been notified via the developer portal that image endpoint responses will change structure during the transition window.

The city has not published a cost figure for the full project. Anyone needing access to specific archival images during the audit period has been advised to submit requests directly to the Arxiu Fotogràfic at its Sant Pere Més Alt location, where staff are maintaining a parallel manual fulfilment service while the automated systems are being reconfigured.